for (var x = 0; x < img.width; x++) {
    for (var y = 0; y < img.height; y++ ) {
      // Calculate the 1D location from a 2D grid
      var loc = x + y*img.width;
      // Get the R,G,B values from image
      var r,g,b;
      r = red (img.pixels[loc]);
      g = green (img.pixels[loc]);
      b = blue (img.pixels[loc]);
      // Calculate an amount to change brightness based on proximity to the mouse
      var maxdist = 50;//dist(0,0,width,height);
      var d = dist(x, y, mouseX, mouseY);
      var adjustbrightness = 255*(maxdist-d)/maxdist;
      r += adjustbrightness;
      g += adjustbrightness;
      b += adjustbrightness;
      // Constrain RGB to make sure they are within 0-255 color range
      r = constrain(r, 0, 255);
      g = constrain(g, 0, 255);
      b = constrain(b, 0, 255);
      // Make a new color and set pixel in the window
      var c = color(r, g, b);
      //color c = color(r);
      pixels[y*width + x] = c; //???
    }
  }
  updatePixels();
}